In this paper we propose to present the biochemical modifications in children and adolescents with HIV infection/AIDS undergoing antiretroviral therapy (ART). We have carried out a retrospective study on 200 HIV-seropositive children registered in our department, without any prior workup modifications, in which antiretroviral therapy was initiated. In all patients we have monitored serum glucose, amylasemia, natremia, and liver enzymes. Most of the biochemical modifications were mild and moderate and did not necessitate cessation of therapy. In only 2 cases, modifications were severe enough to impose a temporary interruption of the ART: one case with elevated triglycerides and one case with elevated liver enzymes. After 24 months of ART, approximately 11.5% (23/200) of the monitored patients had biochemical modifications: 3.5 % elevated triglycerides, 5% elevated liver enzymes, 2.5 % hyperamylasemia, and 0.5 % hypernatremia. Biochemical modifications were more significant in patients who received prior antiretroviral therapy, particularly those who received protease inhibitors (PIs) in comparison to patients naive to ART.